SPRG Seminars
September 25, 2012:
"Fermi LAT observation of high energy emission from Solar Flares"
Nicola Omodei, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA
The Fermi Large Area Telescope (LAT) is the most sensitive instrument ever deployed in space for observing gamma-ray emission >100 MeV. This has also been demonstrated by its detection of quiescent gamma-ray emission from pions produced by cosmic-ray protons interacting in the solar atmosphere, and from cosmic-ray electron interactions with solar optical photons. The Fermi LAT has also detected high-energy gamma-ray emission associated with GOES M-class and X-class X-ray flares, each accompanied by a coronal mass ejection and a solar energetic particle event. During the impulsive phase, gamma rays with energies up to several hundreds of MeV have been recorded by the LAT. Emission up to GeV energies lasting several hours after the flare has also been recorded by the LAT. The focus of this presentation will be the results from the observation of the impulsive emission phase in solar flares, including the modest GOES M2-class solar flare SOL2010-06-12T00:57 as well as more-recent detections, such as the bright event of March 2012.